Air-compressor.



L. CLAWSON.

AIR COMPRESSOR.

l GRM/MA.

rHE NORRIS PETERS C0.. PNOYO'LIYNQ.. WASHINUTUN, n L;

L. CLAWSON.

AIR COMPRESSOR.

MfPLIUATIoN FILED JUNE 23,1913.

Patented Sept. 29, 1914.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

LEROY CLAWSON, 0F HALL, MONTANA, `A SSIC'hTOEt OF ONE-HALF TO CHARLES LAVERN cLAWsoN, or HALL, MONTANA. v

Ain-COMPRESSOR.

Specification of Letters Patent.

Application mea Jene 23, 1913. serial No. 775,450.

`may be compressed easily and rapidly and fed to a storage tank or reservoir from which it may be carried to the point of use.

The apparatus is adapted for useupon air brakes or other machinery which may be adapted for operation by fluid under pressure.

One object of the invention is to provide means whereby the pressure in the reservoir or storage tank may be automatically relieved when it has reached a predetermined degree without requiring a stoppage Vof the air compressor.

The invention also has for'its object the provision of a simple construction vwhereby the several parts may be readily assembled and will be held securely in their proper op-` erative relations to the end that the dura-` bility and efficiency of the apparatus may be increased, and the inventiony also .seeks to provide novel forms vof pist-ons and a novel valve for controlling the flow ofthe fluid through the compressor. i

These stated objects of the invention, and

such other incidental objects as will appear from the following description, `are attained in the use of a mechanism such as is illustrated in the accompanying drawings, and the invention consists in certain novel fea tures whichwill be particularly pointed out in the claims following the description. y

In the drawings: Figure 1 is a longitudinal section of an air compressor embodying my invention showing the pistons on the intake stroke; Fig 2 is a similar view sho-wing the pistons a out to complete the compression stroke; Fig. 3 is a transverse sec-l tion on the line 3 3 of Fig. 1; Fig. 4 is a transverse section on the line 4-4 of Fig. 1. Fig. 5 is a transverse section on the line 5 5 of Fig. 2.

In carrying out my invention, I eInplDy4 2L bed or `base l which maybe of any convenientconstruction, and upon the said bed I secure a compound cylinder consisting of a relatively larger intake cylinder 2 and a relatively smaller discharge cylinder 3, the said cylinders being disposed in axial alinement, as clearly shown. The cylinders are preferably cast in one integral body having their meeting ends integral and their outer endsopen and provided with annular radial flanges, as clearly shown in Figs. 1 and 2. To the outer end of the larger cylinder 2 I secure, by bolts or equivalent devices, a

head 4 having inlet openings .5 therein, and

to the outer open end of the cylinder' 3, I secure a valve body 6 in a similar manner. Within the cylinders 2 and 3 a piston rod 7 is concentrically disposed andthispiston rod and the parts co-acting therewith are as` sembled within the cylinders before the head 4 and the valve body 6 aresecured to the cylinders, as will be readily understood. The piston rod has one end extended through the head 4 and so arranged that `therod may be reciprocated within the cylinders. The rod is smooth on its exteriorsurfacaexcept asl hereinafter described, and'its `inner `extremity 'is slightly reduced and threaded, as shown at 8. y

Upon the threaded extremity of the piston rod is mounted the inner piston consisting ofa tubular body 9 which is internally threaded to engage the threaded extremity 8 and is provided with an annular flange orf disk-like inner extremity which extends. radially to and fits closely against the inner surface of the cylinder 3. Through the annular flange or disk-like extremity `of this tubular "body 9 are formed openings 10- for thepassage of the 'compressed air, as will be hereinafter set forth. A second tubular body 11 is threaded upon the extremity of the piston rod and is turned home against the first- Pateneed sept. 29, 1914.

mentioned tubular body 9 and this 'tubular l member 11 is also provided with an. annular flange .or disk-like .extremity indicated at 12 and provided with openings 13 through which the compressed air may escape. After these piston members have been assembledv upon the rod the extremity ofthe rod may be upset so as to retain the piston 1n msition, Between theannular anges o` the for.'convenience in assembling and also piston members is fitted a cylindrical valve or ring 14, the inner diameter of which is somewhat greater than the outer diameter of the tubular bodies 9 and 11 and the length of which is somewhatless than the distance between the said annular fianges. This ring or annular valve is preferably constructed of two members secured together by rivets to facilitate the placing or renewing of packing 16. around the valve. The portion of the bers 19 and' 20 are provided with annular fianges'or disk-like extremities 22 and 23, respectively, and openings 24 are formed .through the ysaid flangesl or members, as

clearly shown, the openings 24 in the member1p9rbeing disposed near the outer annular edge thereof, while the openings in the member areA disposed approximately at the outersurface of the tubular portion of lthe member. A valve 25 is fitted between the flanges of the piston members'19 land 2O v and this valve corresponds in construction to the vvalve y14,.being composed of a twopartlring having its parts secured together by rivets orbolts 26 and carrying an annular packing 27 which bears against the inner surface of the cylinder 2. The inner I 'dia-meter of this annular valve is somewhat greater than .theexternal diameter of the piston and the length of the valve is somewhat less than ther distance between the flanges 22 and 23.

, Between the two pistons, T provide around the` piston rod means for controlling the flow of the fluid from the cylinder 2 tothe cylinder 3 in the form ofV a peculiarly constructed cheek valve. Thisvalve consists of two annularbodies 2 8 and 29 fitted upon the piston 'rodvxandhavinga threaded engagement with eachother.; The` body 28 is provided with an internally'threaded ringor annular axial flange 30 lat its outer` edge, while the body 29 `is provided` with an externally threaded ring orannular axial flange4 31 whichis arranged inwardly from the edge of the said body and isadaptedt o fit withinand engage the 30 ofthe body 28. Between the two *bodies 28 and 29 a packing `32 is fitted laroundth'e piston.rod and this packing will be compressed when themember 29 is fitted to the member 28 so that a `frictional engagement witlrthe piston rod will be effected and the valve caused to travel with the'piston rod. To insure and maintain this frictionalengagement of the packing with the piston rod a compression spring 32 is fitted around the packing and tends to compress the same around the rod. This spring may be of any convenient form and is so tempered and shaped that it tends to contract around the packing and, therefore, automatically compensates for wear upon the packing.

To limit the travel of the valve in.` one direction a vstop ring 33 is secured within the inner end of the larger cylinder 2 by bolts 34 passing through the inner head of said cylinder and the said head presents an internal annular shoulder which will limit the movement of the valve in the opposite direction. The stop ring 33 has an inner diameter somewhat greater than the minimum external diameter of the valve body 28 so that the said body, in the illustrated form, may enter the stop ring in the operation of the apparatus without arresting the flow of the fluid. The maximum diameter of said body, however, is greater than the internal diameter of the stop ring, thereby providing an external annular shoulder 36 which is adapted to abut against the. stop ring 33 land arrest the movement of the valve and also, by such action, cut off the fiow of fiuid between the two cylinders. The valve member 29 is provided with external pins or lugs 37 which are adapted to impinge against the stop shoulder of the cylinders and thereby arrest the movement of the valve toward the cylinder 3 without cutting `off the flow of the fluid.

The valve body 6 is secured directly to and against the annular' flange at the outer end ofthe cylinder 3 and contains an internal valve chamber 38 which communicates with the interior of the said cylinder 3Q Within this chamber 38 is mounted a valve consisting of a disk 39 having notches 40 in its edge and having a stem 1-1 extending through the valve chamber to aid in guiding the valve. Around this stem 41 is coiled a spring. 42 which tends to normally hold the valve to and against the end of the cylinder 3 so as to prevent the flow of fluid from the cylinder. This position of the valve is illustrated in Fig. 1. llllhen the pressure upon the valve overcomes the tension of the spring 42 the valve will move away from the end of the cylinder, as shown in` Fig. 2, and the compressed fluid may then flow through the notches 40 into the valve chamber 6, whence it will escape through a pipe 43 to the reservoir or storage tank. A check valve 44 is preferably fitted in the outlet pipe 43 to prevent back flow of the fluid. A relief chamber 45 is formed in the valve body 6 beyond the valvechamber 38 and this relief chamber 45 `has avent or outlet 46 opening into the atmosphere. Commimication between the valve chamber 38 and the relief chamber 45 ishad through small passages 47 formed in the wall separatingthe two chambers, and flow through these passages is normally cut off by a valve i 48 arranged within the chamber 38 and eX tending over the said openings, as clearly shown. Thisvalve 48 has a valve stem 49 extending through the outer wall `of the valve body andhaving a hollow portion 50 which serves as a guide and support for the end of the valve stem. 41. The outer eX-jv tremity of the valve stem 49 is arranged to bear against one endof a lever 51 whichvis fulcrumed, as at 52, upon the valve body and has its opposite end pivotally connected to the outer end of a piston rod 53. This piston rod 53 is externally threaded and a presser plate 54 is mounted thereon to bear upon packing 53 which is arranged around the rod and within the cylinder 55 provided therefor. This cylinder 55 is preferably formed within the body 6 and a piston mem# ber 56 is carried by the inner end ofthe piston rod, the packing 53 being confined between said piston member and the presser plate. It will be readily understood that by adjusting the presserplate towardthe piston, the packing will be compressed to compensate for wear so thatleakage may be prevented throughout the life of the apf paratus. Thepistonis completed by a hol-` low body 58`vwhi`ch fits around the enlarged head 59 of the piston rod 57` and has anannular flange 60 through which and the mem-` ber 56 rivets or bolts 61 are inserted to secure the said members together.

The cylinder 55 is open at its outer end and, at itsinner end,.is"in communication with a governor or pressure chamber 62 of less diameter than the cylinder, an annular shoulder 63 being thereby; provided against which the liange 60 ofthe piston member 58 may impinge. A pipe 64 leads from'thereservoir or storage `tank `into the pressure chamber 62 and when the'iiuid admitted to said chamber reaches a predetermined pres-` sure the piston 56 58 will be forced outwardly, thereby rocking the lever 51` upon its fulcrum and, consequently, forcing the valve 48 away fromthe passages47 so that the air driven into the valve body by the compressor will not flow -to the tank but will escape into therelief chamber 45 and thence through the vent 46 to the atmosphere. Adjacent the piston 56-58 the'piston rod 57 is constructed with an angular portion 65 upon which ismounted a nut or gland 66 adapted to engagethe internally threaded wall of the pressure Chamber 62.

. tion,

By rotating the piston rod the gland will `be caused to travel upon its i threaded engagement withthe walls of the pressure chamber land will thereby be ydrawn inwardly in said chamber so as tocompress `the packing67 placedin astuling box 68 whichmay be conveniently formed integral with the valve body, jas illustrated, and to `prevent the gland' 66 turning upon and `thereby wearing awayl the said packing, a 3. washer 69 is inserted between the gland and tremity `of the piston rod'is made angular,y vas shown at 7 3, so that it may be engaged bya wrench or other suitable tool and r0- ytated to assemble and adjust the parts.

It is thoughtthe operation of the appaing; description, taken in connection with the accompanying drawings. VWhen the plsltonrod 7 is moved inthe direction indicated by the arrow in Fig. l,` the pistons mounted upon the said rod will,sof course, `move in the same direction andthe `valve 28-,29 will move likewise rin the same direction until arrested by the shoulder 36 abutting thering 33. wThe valve rings 14 and the piston 4ratus will be understood from the forego- 25, being in frictional engagement withH the respective cylinders through the packing in the outer` annular surface of said valves, will tend ,to remain atrest until the annular flanges 12 and 23, respectively, im-

pinge against ythe valves, whereupon theA valves will move with the pistons. This achowever, provides, open `passages through the front ends of the pistonsand between the bodies of the pistons-and the ioo valves to the space in rear of each piston,l i

while iowfr'om one cylinder to the other -cylinder is preventedl by the check valve 284-29.

Apartial vacuum will be established .within the larger cylinder between the piston therein and-the checkvalve 1and,1

consequently, air or lother Huid will flow through the inlet openings 5 and through the passages provided therefor between the .piston and the valvecarried by the same into vthe space between said` piston and they;

check valve. Atthe same time, any Huid whichmay have been in the smaller cylinder will be compressed between the piston therein and the check valve and will, consequently,be causedto iow through the said;

piston to the valvef39. Upon the return movement of the `piston rod in the directionindicated by the arrow in Fig. 2, the

check valve; 284-29 will. be` carried, to the 'positionfshown in said Fig. 2 so that the vfluid may flow around the said valve from the cylinder -2l into the cylinder 3. The

valves upon lthefrespective pistons will also be cau'sedftofit against the annular flanges 9 fand 19' so as to cover the openings 10 and 24,VA respectively, and, consequently, the fluid will-fbe forced by the said pistons toward i the valve 23"-29 and the valve 39, respec- 'v the valve 39 willy be'compressed suiliciently tively.` The iuidfbearing directlyy against i to overcome the tension of the spring 42 and said valve will then open to permit the liuid -to pass into the pipe 43 and'then flow into lathe-reservoir. The nuts 72 upon the piston frovd"57 will be adjusted so as to put the lShould the Ipressure-in the reservoir, however, exceed that determined by the tension of the spring 70, 'the governor piston will .be moved outwardly7 vso that the lever 51 will bevibrjated and the continuedoperation of 35' u v'working against less resistance than when it is 'storing the air within the reservoir, and

vehicles.

i; j working in said cylinders', valves carried by jthe"pist`ons, a piston rod common to said "pistons, a check valve slidablyv mounted upon a rod between the pistons .and in fric-l the compressor vwillv then drive the compressed fluid through the' vent 46 and not into the reservoir, as previously stated.A

When the pump is driving the air directly vthrough the relief lchamber and the vent 46 finto the atmosphere, itwill, of course, be

thel high temperature of the cylinders due to the compression of thev airtherein 'in the ordinary vvoperationy of the apparatus will be lowered. As this venting of the ma- *chine may occur ordinarily with more on less frequency, the excessive over-heating of the-.cylinderswill be avoided.V y

It will be readily noted that I have pro- 'vided a very -compact apparatus by which theair orv other fluid may be rapidly com- -pressed'to any desired degree-and the pressure-in the reservoir or storage tank prevented from passing the safety point.'

Theapparatus maybe used wherever a supply of compressed airis necessary or desirable` and will be found especially advantageous in public garages to maintain a sup- 55 plyv of compressed air for quickly inilating the pneumatic tires of automobiles or other WhatIcl-aimis:-' v 1. A fluid vcompressing apparatus comprising axially alined cylinders, pistons tional engagement with the rod, and means on the cylinders to limit the movement of the check-valve.

2. A fluid compressing apparatus comprising axially alined cylinders, pistons working therein and comprising bodies having spaced annular flanges radiating therefrom and provided with fluid passages out of axial'alinement, valve rings in frictional engagement with the respective cylinders between said lflanges and spaced from the respective bodies, a piston rod connecting said pistons, and a check-valve held frictionally on the rod between the pistons.

3. In a fluid compressor, axially alined cylinders, pistons working therein, a piston rod connecting said pistons, a valve ring frictionally held upon the piston rod between the pistons and adapted to impinge against .the end of the smaller cylinder, and

a stop ring secured within the larger cylinder and projecting into the path of movement of said valve.

4. In a fluid compressor, the combination of a. cylinder having an inlet at one end and an outlet at the opposite end, a piston working therein, a valve body secured to and litting over the outer end of the cylinder, a valve within said body controlling the flow from the cylinder and adapted to close the outlet end thereof, an outlet from said valve body beyond said valve, and a pressure-controlled vent in said body beyond said outlet.

5. In a fluid compressor, the combination of a cylinder, a piston working therein, a valve body secured to andlitting over the end of the cylinder, said valve body having a relief chamber and a valve chamber, a vent leading from the said relief chamber, an outlet from the valve chamber, a valve within the valve chamber normally closing the end of the cylinder, and pressure-controlled means for establishing communication between the valve chamber and the relief chamber.

6. In a fluid compressor, the combination of a cylindena piston werking therein, a valve body securedv to and fitting over the end of the cylinder, an outlet from saidV valve body, a valve mounted in said body and normally closing the end of the cylinder, a pressure chamber within the valve body, an inlet pipe communicating with said chamber, a piston normally closing the said pressure chamber, means controlled by said piston for diverting the fluid from the outlet of the valve body, and means for holding the said piston normally against the pressure within the pressure chamber.

7. In a fluid compressor, the combination of a cylinder, a piston working therein, a valve body secured to and fitting over the end of the cylinder, means within said body to control the flow from the cylinder, a pressure chamber Within the said valve body, an inlet pipe leading into said pressure chamber, a piston rod extending through the said pressure chamber, a piston swiveled on said i rod and normally closing the said pressure chamber, a tension device on said piston rod external to said chamber, means Within the said chamber for adjusting the said piston rod, and a vent for the valve body connected with said piston and actuated thereby.

In testimony whereof I aX my signature in presence of two witnesses.

\ LEROY CLAWSON. [n s.] Witnesses: J. D. YOAKLEY,

SAMUEL N. AGKER.

it J

Copies of this patent may be obtained for nve cents each, by addressing the "ommissioner of Patents,

Washingtom D. C. 

